Among the ceramic materials, calcium phosphate-based ceramic material is a main component of bone and tooth, has superior biocompatibility, and is superior in the safety. Therefore, it is widely utilized and studied as a biomaterial such as a medical or dental implant material to be implanted in the living body such as artificial bone, artificial dental root and the like, scaffold for cell culture to be used for regenerative medicine and the like, a drug carrier for drug delivery system (DDS) and the like.
However, when a bone defect is large, it is difficult to repair the bone with a single ceramic material. In addition, it is difficult to repair cartilaginous parts having a lower repair function than bone.
With such background, the development of an implant material, wherein cells having a tissue repair capacity such as bone marrow-derived mesenchymal stem cells and the like are seeded on a porous ceramic material, is ongoing.
In such implant material, when bone marrow-derived cells having a tissue repair capacity are seeded on a porous ceramic material, it is desirable to remove red blood cells unnecessary for tissue regeneration from the bone marrow blood, and seed only the useful cells such as stem cells and the like in a concentrated state.
As a production method of an implant material seeded with cells, (1) a method of adding dropwise a liquid containing cultured cells, (2) a method of immersing a porous body in a liquid containing cells, (3) a method of loading a pressure with a piston and the like on an airtight container containing a liquid containing cells and a porous body, (4) a method of loading a centrifugal force on a container containing a liquid containing cultured cells and a porous body, and the like are known.
For example, patent documents 1-4 describe seeding methods using a centrifugal force. In 1 and 4, cells collected from the patient and cultured was seeded and, in 2 and 3, all the cells were seeded on a material, where the cell distribution state in a liquid cannot be controlled.
In patent document 5, a method including placing a porous body in coexistence with a liquid in a container, sliding a piston on the inner face of the container to allow penetration of the liquid into the porous body in advance, and seeding the cultured cells is disclosed. However, even this method cannot control the distribution state of the cells. Therefore, it is difficult by a conventionally-known method to selectively seed cells in a liquid, which are in a concentration state.